Graphene Assisted Ultrafast Nonlinear Optics: From all-optical modulation to time-resolved spectroscopyExport this event to calendar

Thursday, September 7, 2017 — 3:30 PM EDT

Behrooz Semnani, PhD candidate, Department of  Electrical and Computer Engineering, University of Waterloo  

Recent rapid advancements in nanofabrication technologies have widened the realm of possibilities in nanophotonics, nonlinear and sub-wavelength optics. Realizing nonlinear optics in subwavelength scale paves the way for low cost integrated photonics. Ultra-high-Q photonic crystal nanocavities and nanostructured materials are examples of such structures. Those structures offer very small mode volume guaranteeing highly enhanced field intensity.  However, the region of nonlinear interaction is limited to the mode extend. This hinders the adoption of the bulk nonlinear mediums for nonlinear optical applications. To circumvent this issue, the integration of the recently discovered 2D-materials and extremely high Q photonic crystals and plasmonic structures are proposed.

Among 2D materials, graphene has been demonstrated to be optically nonlinear. The band structure of graphene differs substantially from that of other known semiconductors. The symmetries of the graphene lattice entail significantly strong nonlinear optical properties making graphene a compelling candidate for integrated nonlinear optics. Though some metals may also exhibit strong nonlinearity, they are generally opaque and highly refractive. Unlike metals, graphene is almost transparent maintaining the optical structure intact. In the first part of the seminar, our theoretical models revealing the strange root of optical nonlinearity in graphene will be discussed. Our theoretical molds are complimented by experimental results. 

Emphasise is placed on an on-chip platform for ultrafast all-optical amplitude modulation. Our experimental results indicate strong all optical modulation in a graphene-clad planar photonic crystal nanocavity. This development relies heavily on the unique properties of graphene, including its fast carrier dynamics and the special phonon induced relaxation mechanism. The potential application of graphene based all-optical modulation in time resolved nonlinear spectroscopy will be discussed. 

Location 
QNC - Quantum Nano Centre
1201
200 University Avenue West

Waterloo, ON N2L 3G1
Canada
Event tags 

S M T W T F S
30
31
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
1
2
3
  1. 2020 (20)
    1. October (1)
    2. September (2)
    3. August (2)
    4. June (4)
    5. April (1)
    6. March (3)
    7. February (5)
    8. January (2)
  2. 2019 (139)
    1. December (7)
    2. November (10)
    3. October (7)
    4. September (5)
    5. August (10)
    6. July (16)
    7. June (13)
    8. May (15)
    9. April (15)
    10. March (11)
    11. February (20)
    12. January (12)
  3. 2018 (144)
  4. 2017 (131)
  5. 2016 (88)
  6. 2015 (82)
  7. 2014 (94)
  8. 2013 (91)
  9. 2012 (122)
  10. 2011 (117)
  11. 2010 (41)
  12. 2009 (4)
  13. 2008 (1)
  14. 2005 (1)
  15. 2004 (3)